Two-component coating application systems are known in which each of the components are fed through a spray gun in the desired ratio for application to a substrate. Prior to feeding the components to the spray gun, they may pass through proportioning valves which control the mix ratio of the components. A static mixer in the form of a SEMCO type spiral mixer which allows paint to flow over elements prior to application/dispensing may then be conventionally used to mix the components before they are introduced into the spray gun. However, it would be desirable to provide a multi-component spray coating system in which the components are more completely mixed prior to spray application.